Intracorneal lens having a central hole

ABSTRACT

A lens provided for being implanted in a cornea, which comprises an optical portion having an optical axis; and a hole through the lens. The hole is concentric with the optical axis and the dimension and shape of the hole are chosen so that the hole does not impair the optical properties of the lens, but remains visible to one that manipulates the lens.

BACKGROUND OF THE INVENTION

The present invention generally relates to intracorneal lenses, and tomethods for correcting vision by insertion of an intracorneal lens in aneye of a patient.

It is known to provide an alternative to spectacles and extra-ocularcontact lenses by using intraocular or intracorneal lenses forcorrecting deficiencies in visual acuity.

Intraocular lenses (IOLs) are typically provided for being inserted inthe chamber of the eye, in the capsular bag or between the iris and thecrystalline lens of the eye. Intraocular lenses typically comprise acentral portion having optical corrective power, and a peripheralsupport portion. The support portion, known as a haptic, is generallyprovided to help manipulate the lens and also generally allowsmaintaining the lens in a given position within the eye.

US Patent Application Publication No. U.S. 2004/0085511 A1 (Uno et al.)discloses an intraocular lens provided for being inserted in theposterior chamber of an eye. The lens has an optical portion and asupport portion. When the lens is arranged in an eye, the edges of thesupport portion contact the outer edges of the posterior chamber,between the edges of the iris and the ciliary body. The support portionis dimensioned to maintain the optical portion properly aligned with theiris. The optical portion is dimensioned so that the opening of the irisnever exceeds the diameter of the optical portion. The inside of an eyeis filled with aqueous humors, and the lens comprises grooves and poresto allow the flow of the aqueous humor within the eye.

PCT/US05/14439, from the present inventors, discloses an intraocularlens provided for being inserted in the posterior or anterior chamber ofan eye. The lens has an optical portion and a support/haptic portion.The lenses arranged in the anterior chamber of an eye are held inposition in the eye by the interaction of the haptic portion with theiridocorneal angle of the eye. The lenses arranged in the posteriorchamber of an eye are held in position in the eye by the interaction ofthe haptic portion with the angle between the edges of the iris and theciliary body of the eye. The lenses comprise grooves and pores to allowa flow of the aqueous humor within the eye. Further, the haptic portionof the lenses comprises orientation labels. The lenses can be insertedin the eye in a folded configuration, and unfolded within the eye. Theorientation labels help the surgeon determining the position of theanterior and posterior faces of the lenses.

Intracorneal lenses differ in a number of aspects from the intraocularlenses. Intracorneal lenses are provided for being inserted within thecornea instead of within the chambers of the eye. Because intracorneallenses are provided for being inserted within the cornea, they aresmaller than intraocular lenses. Since intracorneal lenses andintraocular lenses have different positions with respect to thecrystalline of the eye, an intracorneal lens and an intraocular lensmust have different optical properties to correct a same abnormality ofan eye.

FIG. 1 shows a cross section of an eye having a cornea 2. A variety ofdevices have been developed to prepare an opening in the cornea of aneye having visual abnormalities. An intracorneal lens is then insertedand maintained in the opening of the cornea, for example as shown inFIG. 2. FIG. 2 shows an intracorneal lens 4 in an opening 6 of a cornea2 of an eye.

As detailed above, intraocular lenses have support portions thatinteract with the natural edges of the eye chambers to align the lenseswith the eye. However, an intracorneal lens is inserted in a man-madeopening in the cornea, which has no natural edges with which the lenscould interact to align the lens with the eye.

It is nevertheless generally necessary to align precisely anintracorneal lens with a predetermined axis of the eye to obtain adesired correction of an abnormality of the eye.

PCT2001US25376 to Feingold discloses a device provided for cutting in acornea a pocket that is precisely positioned and dimensioned, andintracorneal lenses provided for being inserted in such pockets. In apreferred embodiment, the pocket is substantially circular with alateral access opening smaller than a diameter of the pocket. Lenses areprovided for having a diameter smaller than the diameter of the pocketoutside of the cornea, and for swelling to the diameter of the pocketonce in the cornea. This promotes retention of the lens in an alignedposition in the cornea.

However, all intracorneal lenses may not be provided for swelling onceintroduced in the cornea. Further, cutting a pocket having preciseposition and dimensions can be difficult and/or time consuming.

Accordingly, there is a need for a device or a method that would allowimplanting an intracorneal lens without having to use a lens providedfor swelling once introduced in the cornea, or without having to cut apocket of precise position and dimensions in the cornea.

SUMMARY OF THE INVENTION

The present invention satisfies the above-noted need by providing a lenshaving a central hole with a size small enough to avoid impairing theoptical properties of the lens, and big enough to allow the surgeon tosee the hole and to align the hole with a mark showing an axis of theeye, when implanting the lens in the cornea.

In particular, the present invention provides for a lens provided forbeing implanted in a cornea, comprising an optical portion having anoptical axis and a hole through the lens; wherein the hole is concentricwith the optical axis and wherein the dimension and shape of the holeare chosen so that the hole does not impair the optical properties ofthe lens, and remains visible to one that manipulates the lens.

According to an embodiment of the invention, the hole has a diametercomprised between 50 and 500 micrometer.

According to an embodiment of the invention, the optical axis of thelens passes through the center of the lens.

According to an embodiment of the invention, the hole has a diameterlarger than 100 micrometer.

According to an embodiment of the invention, the hole has a diametersmaller than 200 micrometer.

According to an embodiment of the invention, the lens comprises at leastone circular non-optical portion having no optical power and beingconcentric with the hole.

According to an embodiment of the invention, the non-optical portion issurrounded by the optical portion.

According to an embodiment of the invention, the hole is a single hole.

According to an embodiment of the invention, the diameter of the holevaries along the depth of the hole.

According to an embodiment of the invention, a first portion of thewalls of the hole follows a first portion of a cone, the diameter of thehole decreasing from a first outer diameter, at an entrance of the hole,to an inner diameter smaller than the first outer diameter, at anintermediate position within the hole, and a second portion of the wallsof the hole follows a second portion of a cone, increasing from theinner diameter to a second outer diameter, at the other entrance of thehole.

According to an embodiment of the invention, a first portion of thewalls of the hole follows a first portion of a torus center, thediameter of the hole decreasing from a first outer diameter, at anentrance of the hole, to an inner diameter smaller than the first outerdiameter, at an intermediate position within the hole, and a secondportion of the walls of the hole follows a second portion of a torus,increasing from the inner diameter to a second outer diameter, at theother entrance of the hole.

According to an embodiment of the invention, a first portion of thewalls of the hole follows a portion of a cone, the diameter of the holedecreasing from a first outer diameter, at an entrance of the hole, toan inner diameter smaller than the first outer diameter, at anintermediate position within the hole, and wherein a second portion ofthe walls of the hole follows a portion of a torus, increasing from theinner diameter to a second outer diameter, at the other entrance of thehole.

According to an embodiment of the invention, a third portion of thewalls of the hole, between the first and second portions of the walls ofthe hole, follows a cylinder having a diameter equal to the innerdiameter.

According to an embodiment of the invention, the walls of the holefollow a cone from one entrance of the hole to the other entrance to thehole.

According to an embodiment of the invention, the walls of the holefollow a cylinder from one entrance of the hole to the other entrance ofthe hole.

According to an embodiment of the invention, each of the anterior andthe posterior surfaces of the lens comprises at least a portion of oneof the following surface types: spherical surface, with a single focus;spherical surface, with two or more focuses; non-spherical surface, witha progressive focus zone; toric surface; and flat surface.

According to an embodiment of the invention, at least one of theanterior and the posterior surfaces comprises a stepped portion.

Another embodiment of the present invention relates to a method ofcorrecting optical properties of a cornea of an eye along apredetermined axis of the eye, the method comprising:

marking the cornea of the eye at the intersection of the surface of thecornea with the predetermined axis;

creating in the thickness of the cornea an opening provided forreceiving a lens in the vicinity of the predetermined axis, wherein thedimensions of the opening allow the position of the lens to be adjustedin the opening;

inserting a lens as provided in any of claims 1 to 17 in the opening;and

aligning the hole of the lens with the marking of the cornea.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a cross-section of an eye.

FIG. 2 is a sectional view of the anterior portion of an eye having anintracorneal lens disposed within the cornea of the eye.

FIG. 3 is a cross-sectional view of a corneal pocket for receiving anintracorneal lens.

FIG. 4 a shows an elevation view of a lens according to an embodiment ofthe present invention.

FIG. 4 b shows a cross-section of the lens of FIG. 4 a.

FIG. 4 c is a close-up view of the center of FIG. 4 b.

FIG. 4 d depicts a hole area of a particular embodiment.

FIG. 5 a illustrates a method according to the present invention.

FIG. 5 b is a top-view of an eye having a cornea with an intracorneallens according to the present invention.

FIG. 5 c is a cross-section view of the cornea of FIG. 5 b.

FIG. 5 d is another cross-section view of the cornea of FIG. 5 b.

FIG. 6 a shows an elevation view of a lens according to anotherembodiment of the present invention.

FIG. 6 b shows a cross-section of the lens of FIG. 6 a.

FIG. 6 c is a close-up view of the center of FIG. 6 b.

FIG. 7 a shows an elevation view of a lens according to anotherembodiment of the present invention.

FIG. 7 b shows a cross-section of the lens of FIG. 7 a.

FIG. 7 c is a close-up view of the center of FIG. 7 b.

FIG. 8 a shows an elevation view of a lens according to anotherembodiment of the present invention.

FIG. 8 b shows a cross-section of the lens of FIG. 8 a.

FIG. 8 c is a close-up view of the center of FIG. 8 b.

FIG. 9 a shows an elevation view of a lens according to anotherembodiment of the present invention.

FIG. 9 b shows a cross-section of the lens of FIG. 9 a.

FIG. 9 c is a close-up view of the center of FIG. 9 b.

FIG. 10 a shows an elevation view of a lens according to anotherembodiment of the present invention.

FIG. 10 b shows a cross-section of the lens of FIG. 10 a.

FIG. 10 c is a close-up view of the center of FIG. 10 b.

FIG. 11 a shows an elevation view of a lens according to anotherembodiment of the present invention.

FIG. 11 b shows a cross-section of the lens of FIG. 11 a.

FIG. 11 c is a close-up view of the center of FIG. 11 b.

FIG. 12 a shows an elevation view of a lens according to anotherembodiment of the present invention.

FIG. 12 b shows a cross-section of the lens of FIG. 12 a.

FIG. 12 c is a close-up view of the edge of FIG. 12 b.

FIG. 13 a shows an elevation view of a lens according to anotherembodiment of the present invention.

FIG. 13 b shows a cross-section of the lens of FIG. 13 a.

FIG. 13 c is a close-up view of the edge of FIG. 13 b.

FIG. 14 illustrates how light rays traverse an embodiment of the lens inFIGS. 12 a-c.

FIG. 15 illustrates how light rays traverse another embodiment of thelens in FIGS. 12 a-c.

FIG. 16 a shows an elevation view of a lens according to anotherembodiment of the present invention.

FIG. 16 b shows a cross-section of the lens of FIG. 16 a and illustrateshow light rays traverse the lens.

FIG. 17 a shows an elevation view of a lens according to anotherembodiment of the present invention.

FIG. 17 b shows a first cross-section of the lens of FIG. 17 a andillustrates how light rays traverse the cross-section of the lens.

FIG. 17 c shows a second cross-section of the lens of FIG. 17 a andillustrates how light rays traverse the cross-section of the lens.

DETAILED DESCRIPTION

The present invention presents means to permanently, yet reversibly,correct defects of vision by disposing a lens in a pocket in a cornea.Various embodiments correct myopia, hyperopia, astigmatism, presbyopia,or a combination of these defects. It is to be understood that thepresent invention is not limited to treatment of these defects, and thattreatment of other eye conditions is also within the scope of theinvention. The correction may be permanent, if it remains satisfactory,and may also be reversed by removing the lens from the cornea.

The lenses according to the present invention are for example providedfor being inserted in a corneal pocket as formed with the corneal pocketKeratome device disclosed in PCT2001US25376 to Feingold. As detailedhereafter, the corneal pocket must be slightly larger than the lenses tolet room to adjust the position of the lens within the pocket.

FIG. 3 shows a cross-section of a cornea 2 wherein a pocket or opening 6has been cut. An access opening 8 allows entering the opening 6.

FIG. 4 a shows a refractive lens 40 according to an embodiment of thepresent invention. As detailed hereafter, lens 40 is provided to beinserted in a cornea opening such as shown in FIG. 3. Lens 40 is aspherical lens, in which both the inner and outer surfaces are portionsof a sphere, as shown in FIG. 4 b. Lens 40 is comprised of a singlecircular optical portion 42 having optical power. Optical portion 42 hasan optical axis 44. As detailed hereafter, in some embodiments of theinvention the lens can comprise a non-optical portion, concentric or notwith the axis 44, within or around the optical portion. The lens canhave a diameter of between 1.5 and 6 millimeter.

The lens 42 further comprises a hole 46 that is concentric with theoptical axis 44 of the lens and that goes through the lens 40. Accordingto the invention, the dimension and shape of the hole are chosen so thatthe hole does not impair the optical properties of the lens, and remainsvisible to one (such as a surgeon) that manipulates the lens. The holehas preferably a diameter comprised between 50 and 500 micrometer. Evenpreferably, the hole has a diameter comprised between 100 and 200micrometer. Even preferably, the hole has a diameter of 150 micrometer.The inventors have found that, surprisingly, a hole having the preferreddimensions does not to impair the optical properties of the lens (is notnoticed by the patient), and at the same time remains visible to asurgeon that manipulates the lens. This discovery was counter intuitivebecause one would think that a hole big enough to be seen by the surgeonwould have to be so big that it would impair the optical properties ofthe lens, for example by inducing edge glare from the edge of the hole.However, this is not the case with the preferred dimensions of the hole.For the present invention, it is considered that if the hole does notinduce a significant glare that can be noticed by a user having an eyebearing the lens, the hole does not impair the optical properties of thelens.

As shown in FIG. 4 c, the walls of the hole can follow a cylinder fromone entrance of the hole to the other entrance of the hole. In order toreduce the glare induced by the hole, the size and shape of the hole arepreferably chosen to minimize the surface reflection area of the hole.FIG. 4 d shows for example that for a thickness of the lens around thehole of 0.03 mm and a hole having a diameter of 150 micrometer, the holesurface area is of 0.014 square millimeter. The thickness of the lensaround the hole can be comprised between 0.07 millimeter and 0.005millimeter. The inventors have found that such a hole surface area doesnot generate a glare that is noticed by a user having an eye bearing thelens.

As detailed hereafter, the walls of the hole can also be different froma simple cylinder to reduce further the surface reflection area of thehole.

A lens according to the present invention allows implementing a methodof correcting optical properties of a cornea of an eye along apredetermined axis of the eye according to an embodiment of theinvention. Such method is for example illustrated in FIG. 5 a.

In step 1, one marks the cornea of the eye at the intersection of thesurface of the cornea and of a predetermined axis along which theoptical properties of the cornea should be corrected. The marking can bemade on the external surface of the cornea using a laser, a sharp and/orpointed device, by using pigmentation or by letting a marker device betemporarily pinned or adhered to the surface of the cornea.

In step 2, one creates in the thickness of the cornea an openingprovided for receiving a lens, such as the opening shown in FIG. 3. Theopening can be created with a corneal pocket keratome as disclosed inPCT2001US25376, which is hereby incorporated by reference herein in itsentirety; or using a laser. The laser may be used and guided undercomputer control, as is well known in the art. A corneal opening may beformed by methods similar to those used during LASIK (laser-assistedin-situ keratomileusis) procedures. Alternatively, a corneal pocket canbe formed using a laser and a mask that shapes the pocket, as disclosedin PCT2007US63568 to Feingold, which is hereby incorporated byreference. Alternatively, a corneal pocket may be formed manually by thesurgeon using hand-held instruments.

A corneal flap (not shown) can be formed as an alternative to a cornealopening.

The dimensions of the opening must be such that they allow the positionof the lens to be adjusted in the opening. The depth at which theopening is made under the external surface of cornea is chosen withregards to what must be corrected in the optical properties of thecornea, to the type of lens to be used, etc. . . . The order of step 1and 2 can be inverted if appropriate.

In step 3, one inserts in the opening a lens according to the invention,with an optical portion having an optical axis and a hole through thelens, wherein the hole is concentric with the optical axis and whereinthe dimension and shape of the hole are chosen so that the hole does notimpair the optical properties of the lens, and remains visible to onethat manipulates the lens. The lens is provided for correcting theoptical properties of the cornea when inserted in the opening and withthe axis of the lens aligned on the predetermined axis of the eye. Thelens and the opening are such that centering the hole on the marking ofthe cornea aligns the axis of the lens on the predetermined axis of theeye. A fluid can be inserted in the opening for easing the introductionof the lens. A canula or a small spatula can be used to move the lens toits desired location.

Then, in step 4, one aligns the hole of the lens with the marking of thecornea. The dimensions of the hole are such that the hole is stillvisible to one that manipulates the lens through the part of the corneaabove the opening where the lens is. The inventors have noted that ifthe diameter of the hole is too large, it may become difficult to alignprecisely the hole with the marking of the cornea. This is for examplebecause the edges of the hole become too remote from the marking to knowif they are equally distant from the marking Also for this reason, thediameter of the hole is preferably of the dimensions detailed above.

The opening of the cornea is self sealing and after a few days, theepithelium covers the access of the opening.

FIG. 5 b show a top-view of an eye 50 having a cornea 52 with anintracorneal lens 54 according to the present invention in a cornealopening 56.

FIG. 5 c is a cross-section view of the cornea of FIG. 5 b along a planeC-C including the predetermined axis 58 of the eye; and FIG. 5 d is across-section view of the cornea of FIG. 5 b along a plane D-D alsoincluding the predetermined axis 58 of the eye and perpendicular toplane C-C. The predetermined axis of the eye can be centered or not withrespect to the cornea, depending on the abnormality to be corrected.

It is known that the cells of the cornea receive nutrients via diffusionfrom the tear fluid at the outside and the aqueous humour at the insideand also from neurotrophins supplied by nerve fibres that innervate it.Oxygen is received through the air. It is known to form intracorneallenses of a biocompatible material that permits sufficient gas diffusionto allow adequate oxygenation of internal eye tissues (such materialsmay include silicone, hydrogels, urethanes or acrylics). However, theinventors have noticed that, when an intracorneal lens is implanted in acornea, providing a hole according to the present invention in the lensseems to enhance the transfer of the nutrients within the cornea, whichis beneficial to the cornea and for example eases the healing of thecornea after implantation of the lens. Furthermore, the inventors havenoted that by providing a flow through the hole, no haze or cloudinesscan be observed in the cornea after a healing period.

Advantageously, the hole of a lens according to the invention passesthrough the center of the lens. The inventors have noticed that, inparticular when the lens has the general shape of a dome, with a concavesurface and a convex surface, arranging the hole in the center of thelens seems to enhance further the transfer of the nutrients within thecornea, which is even more beneficial to the cornea.

FIG. 6 a shows a lens 60 according to another embodiment of the presentinvention. Lens 60 is a spherical lens, in which both the inner andouter surfaces are portions of a sphere, as illustrated in FIG. 6 b.Lens 60 comprises a circular optical portion 62 with an optical axis 64and a hole 66 coaxial with the axis 64. The lens 60 also comprises acircular non-optical portion 68 having no optical power, within theoptical portion 62 and concentric with the optical portion 62.

In some other embodiments of the invention, the positions of the opticalportion (such as optical portion 62 in the embodiment of FIG. 6 a) andthe non-optical portion (such as non-optical portion 68 in theembodiment of FIG. 6 a) can be inverted.

Some other embodiments of the invention can comprise a number ofconcentric optical and non-optical portions alternated in any manner(1-1, 1-2, 2-1, etc. . . . ).

In some other embodiments of the invention, the non-optical portion canbe non-concentric with the axis of the optical portion.

As shown in FIG. 6 c, the walls of the hole can follow a cylinder fromone entrance of the hole to the other entrance to the hole. However, asdetailed hereafter, the walls of the hole can also be shaped otherwiseto reduce the risk of creating a glare on the walls of the hole.

FIG. 7 a shows a lens 70 according to another embodiment of the presentinvention. Lens 70 is a spherical lens, in which both the inner andouter surfaces are portions of a sphere, as illustrated in FIG. 7 b.Lens 70 comprises a circular optical portion 72 with an optical axis 74and a hole 76 coaxial with the axis 74. The lens 70 also comprises acircular non-optical portion 78 having no optical power, within theoptical portion 72 and concentric with the optical portion 72.

As shown in FIG. 7 c, the diameter of the hole 76 varies along the depthof the hole. A first portion of the walls of the hole follows a firstportion of a torus: the diameter of the hole decreases from a firstouter diameter, at an entrance of the hole, to an inner diameter smallerthan the first outer diameter, at an intermediate position within thehole. A second portion of the walls of the hole follows a second portionof a torus, increasing from the inner diameter to a second outerdiameter, at the other entrance of the hole. The radius of curvature ofthe revolved circle of the torus can be comprised between 0.01millimeter and 0.002 millimeter. A third portion of the walls of thehole, between the first and second portions of the walls of the hole, iscylindrical and has a diameter equal to the inner diameter. In FIG. 7 c,the first and second outer diameters are shown equal. However, they canalso be different.

The lens shown in FIGS. 7 a-c is spherical. However, as detailedhereafter, a lens according to the present invention can as well beaspheric.

FIG. 8 a shows a lens 80 according to another embodiment of the presentinvention. Lens 80 is a spherical lens, in which both the inner andouter surfaces are portions of a sphere, as illustrated in FIG. 8 b.Lens 80 comprises a circular optical portion 82 with an optical axis 84and a hole 86 coaxial with the axis 84. The lens 80 also comprises acircular non-optical portion 88 having no optical power, within theoptical portion 82 and concentric with the optical portion 82.

As shown in FIG. 8 c, the diameter of the hole varies along the depth ofthe hole. A first portion of the walls of the hole follows a firstportion of a torus: the diameter of the hole decreases from a firstouter diameter, at an entrance of the hole, to an inner diameter smallerthan the first outer diameter, at an intermediate position within thehole. A second portion of the walls of the hole follows a second portionof a torus, increasing from the inner diameter to a second outerdiameter, at the other entrance of the hole. The radius of curvature ofthe revolved circle of the torus can be comprised between 0.025millimeter and 0.0025 millimeter. In FIG. 8 c, the first and secondouter diameters are shown equal. However, they can also be different.

FIG. 9 a shows a lens 90 according to another embodiment of the presentinvention. Lens 90 is a spherical lens, in which both the inner andouter surfaces are portions of a sphere, as illustrated in FIG. 9 b.Lens 90 comprises a circular optical portion 92 with an optical axis 94and a hole 96 coaxial with the axis 94. The lens 90 also comprises acircular non-optical portion 98 having no optical power, within theoptical portion 92 and concentric with the optical portion 92.

As shown in FIG. 9 c, the diameter of the hole varies along the depth ofthe hole. A first portion of the walls of the hole follows a portion ofa cone, the diameter of the hole decreasing from a first outer diameter,at an entrance of the hole on the anterior face of the lens, to an innerdiameter smaller than the first outer diameter, at an intermediateposition within the hole. A second portion of the walls of the holefollows a portion of a torus, increasing from the inner diameter to asecond outer diameter, at the other entrance of the hole on theposterior face of the lens. The portion of cone followed by the holewalls can belong to a cone formed by rotating a triangle having an angleof 10 to 30 degrees around the axis of the hole.

FIG. 10 a shows a lens 100 according to another embodiment of thepresent invention. Lens 100 is a spherical lens, in which both the innerand outer surfaces are portions of a sphere, as illustrated in FIG. 10b. Lens 100 comprises a circular optical portion 102 with an opticalaxis 104 and a hole 106 coaxial with the axis 104. The lens 100 alsocomprises a circular non-optical portion 108 having no optical power,within the optical portion 102 and concentric with the optical portion102.

As shown in FIG. 10 c, the diameter of the hole varies along the depthof the hole. A first portion of the walls of the hole follows a portionof a cone, the diameter of the hole decreasing from a first outerdiameter, at an entrance of the hole on the posterior face of the lens,to an inner diameter smaller than the first outer diameter, at anintermediate position within the hole. A second portion of the walls ofthe hole follows a portion of a torus, increasing from the innerdiameter to a second outer diameter, at the other entrance of the holeon the anterior face of the lens.

FIG. 11 a shows a lens 110 according to another embodiment of thepresent invention. Lens 110 is a spherical lens, in which both the innerand outer surfaces are portions of a sphere, as illustrated in FIG. 11b. Lens 110 comprises a circular optical portion 112 with an opticalaxis 114 and a hole 116 coaxial with the axis 114. The lens 110 alsocomprises a circular non-optical portion 118 having no optical power,within the optical portion 112 and concentric with the optical portion112.

As shown in FIG. 11 c, the diameter of the hole varies along the depthof the hole. A first portion of the walls of the hole follows a firstportion of a cone, the diameter of the hole decreasing from a firstouter diameter, at an entrance of the hole, to an inner diameter smallerthan the first outer diameter, at an intermediate position within thehole. A second portion of the walls of the hole follows a second portionof a cone, increasing from the inner diameter to a second outerdiameter, at the other entrance of the hole. In FIG. 11 c, the first andsecond outer diameters are shown equal. However, they can also bedifferent.

According to an embodiment (not illustrated), the walls of the hole canfollow a cone from one entrance of the hole to the other entrance to thehole.

The lenses shown in FIGS. 4 a-c and 6 a-c to 11 a-c are all refractivespherical lenses in which both the inner and outer surfaces are portionsof a sphere. However, the present invention is not limited to suchlenses. For example, a lens according to the present invention can be adiffractive lens, for example a multi-step lens, and include an annularseries of lens sections between the outer edge of the lens and thecentral portion of the lens. The greater range and control of refractionpermitted by a multi-step lens is particularly useful for correction ofpresbyopia by the method and apparatus of the present invention.

The annular ridges of the multi-step lens will resist lateraldisplacement, but a multi-step lens may also be given retentionfeatures. A multi-step lens can have an outer surface (anterior orposterior) that is a portion of a sphere, while the other outer surfaceis comprised of a series of annular sections of lenses of decreasingsize.

FIG. 12 a shows a reduced thickness, multi-step lens 120 according to anembodiment of the present invention. The outer surface of lens 120 is aportion of a sphere, as illustrated in FIG. 12 b. Lens 120 comprises acircular optical portion 122 with an optical axis 124 and a hole 126coaxial with the axis 124. The lens 120 also comprises a circularnon-optical portion 128 having no optical power, within the opticalportion 122 and concentric with the optical portion 122. As detailed inFIG. 12 c, optical portion 122 is comprised of a series of concentriccircular rings 1220, 1222, 1224, 1226, etc. . . . formed on the innersurface of the lens in a stepped arrangement. In the embodiment shown inFIG. 12 c, the concentric rings 1220, 1222, 1224, 1226, etc. . . .follow each a plane perpendicular to the axis 124. Further, theconcentric rings 1220,1222, 1224, 1226, etc. . . . are connected to eachother by walls 1221, 1223, 1225,1227, etc. . . . that follow each acylinder having the same axis as the lens. The junctions between therings 1220, 1222,1224,1226, etc. . . . and the cylindrical walls 1221,1223,1225,1227, etc. . . . can be rounded. The external edge of the lens120 can for example be beveled and follow a portion of a cone 1201 thatis concentric with axis 124.

The shape of hole 126 is not shown in FIGS. 12 a-c. However, the hole ofa lens according to the present invention can have any of the shapesshown in the previous figures or any other appropriate shape.

The number and size of the rings 1220, 1222, 1224, 1226, etc. . . .shown in FIGS. 12 a-c is only given as an example. Any appropriatenumber and size can be used. Further, each ring is shown followingparallel planes, but if appropriate each ring or some of the rings canfollow a plane not parallel with the others, or a portion of a cone, ofa sphere, of a tore, of an elliptic, parabolic or hyperbolic surface orof a polyhedron (having flat or non flat surfaces).

Also, the rings 1220, 1222, 1224, 1226, etc. . . . are shown circularand concentric, but if appropriate they can have each a different shapeand be for example elliptic or have different centers.

FIG. 13 a shows a reduced thickness, multi-step lens 130 according toanother embodiment of the present invention. The outer surface of lens130 is a portion of a sphere, as illustrated in FIG. 13 b. Lens 130comprises a circular optical portion 132 with an optical axis 134 and ahole 136 coaxial with the axis 134. The lens 130 also comprises acircular non-optical portion 138 having no optical power, within theoptical portion 132 and concentric with the optical portion 132. Asdetailed in FIG. 13 c, optical portion 132 is comprised of a series ofconcentric portions of cones of decreasing size 1322, 1324, 1326, etc. .. . formed on the inner surface of the lens in a stepped arrangement andhaving each the same axis as the axis 134 of the lens. In the embodimentshown in FIG. 13 c, the portion of cones 1322, 1324, 1326, etc areconnected to each other by walls 1323, 1325, 1327, etc. . . . followingeach a cylinder having the same axis as the lens. The junctions betweenthe portion of cones 1322, 1324, 1326, etc. . . . and the cylindricalwalls 1323, 1325, 1327, etc. . . . can be rounded. In FIG. 13 c, a planering 1320 connects the edge of the lens and the external-most edge ofthe portion of cone 1322. The external edge of the lens 130 can forexample be beveled and follow a portion of a cone 1301 that isconcentric with axis 134.

According to some embodiments of the invention, the portion of cones canalternatively be portions of spheres or portions of toric, elliptic,parabolic or hyperbolic surfaces. Alternatively, each portion of conecan be replaced by a series of portions of cone having different angles.The number and size of the cones shown in the Figures is only given asan example. Any appropriate number and size can be used.

FIGS. 12 a-c and 13 a-c show lenses having an anterior surface that is aportion of a sphere, and a stepped posterior surface. However, a lensaccording to the present invention can alternatively have a posteriorsurface that is a portion of a sphere, and a stepped anterior surface. Alens according to the present invention can also alternatively havestepped anterior and posterior surfaces.

A lens according to the present invention can have a single focallength. Such lenses are generally sufficient to correct simple myopia orhyperopia.

FIG. 14 illustrates how light rays 140 traverse the upper portion of across-section of a lens 120 such as shown in FIGS. 12 a-c in anembodiment where the lens is a lens having a single focal point 142.

However, lenses having variations in either refractive index or lensshape, or both, may be used advantageously as part of the presentinvention to establish a multifocal lens. The focal length of such lensis not constant, but varies across the expanse of the lens. Such lensmultifocality can be used to compensate for presbyopia, by causing oneportion of the light incoming to the eye to be focused if the source isfar away, while another portion of the fight is focused when the sourceis close (as when reading). The effectiveness of such varying focallength lenses relies upon reliable positioning of the lens, as isprovided by the present invention, in order to avoid misalignment of thelens, and to simplify adaptation to a plurality of focal lengths by thevisual processing facilities. For example, presbyopia may be compensatedby situating a small area, for example less than 3 mm diameter, offocal-length reducing lens at the center of the cornea. Such locationwill have greater effect in high-light conditions (as are typical forreading), when the pupil is small, and proportionally less effect underlower lighting conditions, such as night driving, when the pupil islarge. Thus the lens location with respect to the pupil must bemaintained; and the brain will adapt more easily to a non-uniform focusof the eye which is at least constant.

FIG. 15 illustrates how light rays 150 traverse the upper portion of across-section of a lens 120 such as shown in FIGS. 12 a-c in anembodiment where the lens is a lens having three focal points 152, 154and 156.

According to an embodiment of the invention, multifocality may also beaccomplished using a non multi-step lens having non-spherical surfaces.

FIG. 16 a shows an elevation view of a non multi-step lens havingnon-spherical surfaces. A cross section of the upper part of such lensis shown in FIG. 16 b. The lens 160 of FIGS. 16 a-b comprises a centralnon-spherical dome portion 162 that defines a first focal zone 164 alongthe axis 165 of the lens. The central portion 162 is surrounded by aperipheral non-spherical annular portion 166 that defines a second focalzone 167 along the axis 166 of the lens. A hole 168 according to thepresent invention traverses the center of the lens. Non-sphericalsurfaces may be such that a cross-section of the surfaces along the axisof the lens follows a portion of an ellipse, a parabola or a hyperbola.

According to an embodiment of the invention, varying focal length oftoric surfaces of the lens can be used to correct astigmatism. Lensesaccording to the present invention can be multifocal lenses thatsimultaneously correct or compensate various combinations of defectsincluding myopia, hyperopia, astigmatism and presbyopia.

FIG. 17 a shows such a lens 170 according to the present invention. Theanterior outer surface of lens 170 follows a complex toric surfaces.Lens 170 comprises a circular optical portion 172 with an optical axis174 and a hole 176 coaxial with the axis 174. The lens 170 alsocomprises a circular non-optical portion 178 having no optical power,within the optical portion 172 and concentric with the optical portion172.

FIG. 17 b shows a half of a cross section of lens 170 along a plane A-Aparallel to axis 174 shown in FIG. 17 a. FIG. 17 b shows a half of across section of lens 170 along a plane C-C parallel to axis 174 shownin FIG. 17 a.

The outer surface of lens 170 follows a first toric surface along planeA-A, and a second toric surface along plane C-C.

As detailed in FIG. 17 b, optical portion 172 is comprised of a seriesof concentric circular rings formed on the inner surface of the lens ina stepped arrangement, for example in a similar way as in the embodimentshown in FIGS. 12 a-c.

As shown in FIG. 17 b, which also illustrates how light rays traversethe lens, the first toric surface cooperates with the stepped innersurface of the lens such that the lens 170 has a first focal point 1701in plane A-A. On the other hand, as illustrated in FIG. 17 c, the secondtoric surface cooperates with the stepped inner surface of the lens suchthat the lens 170 has a second focal point 1702 in plane C-C.

According to the present invention, the lenses can be formed of abiocompatible material that permits sufficient gas diffusion to allowadequate oxygenation of internal eye tissues (such materials may includesilicone, hydrogels, urethanes or acrylics). Materials which may be usedin forming intraocular lenses are generally known in the art, asdisclosed, for example, in U.S. Pat. No. 5,217,491, the disclosure ofwhich is incorporated by reference herein. Preferably, the lensesaccording to the present invention are deformable.

It should be understood that the foregoing relates to exemplaryembodiments of the invention and that modifications may be made withoutdeparting from the scope of the following claims.

For example, each of the anterior and the posterior surfaces of a lensaccording to the present invention can have at least a portion of any ofthe following surface types: spherical with a single focus; sphericalwith two or more focuses; non-spherical with a progressive focus zone;toric; aspheric and plane. Further, each portion of the anterior and theposterior surfaces of a lens according to the present invention can besmooth or stepped.

The radius of curvature of the anterior and the posterior surfaces of aportion of a lens according to an embodiment of the invention can beidentical or can be different. Further, a surface of a portion of a lenscan have multiple radii of curvature along the perimeter of the section,which may allow the lens to compensate for corneal spherical aberration.

Also, an embodiment of the present invention may comprise anintracorneal lens having an optical portion as described hereabove; anda haptic portion surrounding said optical portion, wherein the hapticportion is corrugated. The intraocular lens may comprise an inner domedportion; and an outer portion having a plurality of tabs disposedperipherally on the outer portion, wherein the domed portion is spacedaxially from the plurality of tabs. An embodiment of the presentinvention may also comprise an intracorneal lens having a centraloptical portion; and an outer haptic portion, wherein the haptic portionincludes an annular portion disposed adjacent to, and radially outwardfrom, the optical portion; a pair of inner arcuate corrugations disposedadjacent to, and radially outward from, the annular portion, the pair ofinner arcuate corrugations disposed on opposite sides of the opticalportion; and a pair of outer arcuate corrugations disposed adjacent to,and radially outward from, the pair of inner arcuate corrugations. Thehaptic may comprise at least one irrigation channel radially disposedwithin said haptic. The arcuate corrugations of the pairs ofcorrugations may be concentric.

The lenses described hereabove comprise each a single hole. However,embodiments of the present invention may comprise additional holes inother parts of the lens. The additional holes can for example beprovided for nutrient transfer but not for alignment, and can have adiameter inferior to the diameter of the central hole. This would renderthe peripheral holes too small to be seen by one that manipulates thelens, but would help not impairing the optical properties of the lens.

The invention is not to be limited to the embodiments previouslydescribed, but is defined by the claims that follow.

1-18. (canceled)
 19. A lens provided for being implanted in a cornea,comprising: an optical portion having an optical axis; and a holethrough the lens; wherein the hole is concentric with the optical axisand wherein the dimension and shape of the hole are chosen so that thehole does not impair the optical properties of the lens, and remainsvisible to one that manipulates the lens.
 20. The lens of claim 19,wherein the hole has a diameter comprised between 50 and 500 micrometer.21. The lens of claim 19, wherein the optical axis of the lens passesthrough the center of the lens.
 22. The lens of claim 19, wherein thehole has a diameter larger than 100 micrometer.
 23. The lens of claim19, wherein the hole has a diameter smaller than 200 micrometer.
 24. Thelens of claim 19, wherein the lens comprises at least one circularnon-optical portion having no optical power and being concentric withthe hole.
 25. The lens of claim 24, wherein the non-optical portion issurrounded by the optical portion.
 26. The lens of claim 19, wherein thehole is a single hole.
 27. The lens of claim 19, wherein the diameter ofthe hole varies along the depth of the hole.
 28. The lens of claim 27,wherein the hole has walls, wherein a first portion of the walls of thehole follows a first portion of a cone, the diameter of the holedecreasing from a first outer diameter, at an entrance of the hole, toan inner diameter smaller than the first outer diameter, at anintermediate position within the hole, and wherein a second portion ofthe walls of the hole follows a second portion of a cone, increasingfrom the inner diameter to a second outer diameter, at the otherentrance of the hole.
 29. The lens of claim 27, wherein the hole haswalls, wherein a first portion of the walls of the hole follows a firstportion of a torus, the diameter of the hole decreasing from a firstouter diameter, at an entrance of the hole, to an inner diameter smallerthan the first outer diameter, at an intermediate position within thehole, and wherein a second portion of the walls of the hole follows asecond portion of a torus, increasing from the inner diameter to asecond outer diameter, at the other entrance of the hole.
 30. The lensof claim 27, wherein the hole has walls, wherein a first portion of thewalls of the hole follows a portion of a cone, the diameter of the holedecreasing from a first outer diameter, at an entrance of the hole, toan inner diameter smaller than the first outer diameter, at anintermediate position within the hole, and wherein a second portion ofthe walls of the hole follows a portion of a torus, increasing from theinner diameter to a second outer diameter, at the other entrance of thehole.
 31. The lens of claim 28, wherein a third portion of the walls ofthe hole, between the first and second portions of the walls of thehole, follows a cylinder having a diameter equal to the inner diameter.32. The lens of claim 29, wherein a third portion of the walls of thehole, between the first and second portions of the walls of the hole,follows a cylinder having a diameter equal to the inner diameter. 33.The lens of claim 30, wherein a third portion of the walls of the hole,between the first and second portions of the walls of the hole, followsa cylinder having a diameter equal to the inner diameter.
 34. The lensof claim 27, wherein the hole has walls, wherein the walls of the holefollow a cone from one entrance of the hole to the other entrance to thehole.
 35. The lens of claim 26, wherein the hole has walls, wherein thewalls of the hole follow a cylinder from one entrance of the hole to theother entrance of the hole.
 36. The lens of claim 19, wherein each ofthe anterior and the posterior surfaces of the lens comprises at least aportion of one of the following surface types: spherical surface, with asingle focus; spherical surface, with two or more focuses; non-sphericalsurface, with a progressive focus zone; toric surface; and flat surface.37. The lens of claim 19, wherein at least one of the anterior and theposterior surfaces comprises a stepped portion.
 38. A method ofcorrecting optical properties of a cornea of an eye along apredetermined axis of the eye, the method comprising: marking the corneaof the eye at the intersection of the surface of the cornea with thepredetermined axis; creating in the thickness of the cornea an openingprovided for receiving a lens in the vicinity of the predetermined axis,wherein the dimensions of the opening allow a position of the lens to beadjusted in the opening; inserting a lens as provided in claim 19 in theopening; and aligning the hole of the lens with the marking of thecornea.